Abrasive Articles, CMP Monitoring System and Method

Abstract

The disclosure relates to abrasive articles useful in chemical-mechanical polishing (CMP), the articles including a substrate with opposite major surfaces, an abrasive material overlaying at least a portion of at least one of the major surfaces, a means for providing CMP information positioned near the substrate, and a transmitter positioned near the substrate and adapted to transmit the CMP information to a remote receiver. The disclosure also relates to a CMP pad conditioner having a means for communicating CMP information, a CMP process monitoring system, and a method for conditioning a CMP pad.

Description

TECHNICAL FIELD [0001]The present invention relates to abrasive articles useful in chemical-mechanical polishing (CMP). The invention also relates to CMP process monitoring systems, and a CMP pad conditioning method.BACKGROUND [0002]Silicon wafers used in semiconductor integrated circuit fabrication typically undergo numerous processing steps, including deposition, patterning, and etching steps. In each manufacturing step, it is often necessary or desirable to modify or refine an exposed surface of the wafer in order to prepare the wafer for subsequent fabrication or manufacturing steps. For example, semiconductor wafers having shallow trench isolation (STI) structures require planarization of the dielectric material prior to further processing.[0003]One method of modifying or refining exposed surfaces of wafers employs a continuous process that treats a wafer surface with a polishing slurry containing a plurality of loose abrasive particles dispersed in a liquid. Typically this slu...

AI Technical Summary

Benefits of technology

[0013]Some embodiments of the present invention may improve the operation of machines used in chemical-mechanical polishing of semiconductor wafers by enabling in situ (i.e. within the CMP machine) monitoring of the thickness and thickness variations in CMP pads used to polish wafers, allowing adjustment of the pad conditioning process to maintain a desired surface shape. In situ monitoring may be concurrent with the polishing operation, or may be intermittent, for example, between polishing steps. In situ monitoring during the CMP process may also prevent damage to the wafer, thereby saving the wafer. Furthermore, close control of the CMP process may allow for tighter specifications to be met and the processing time to be reduced.

[0014]In certain embodiments, the CMP process monitoring system may enable stable CMP process operation, thereby maintaining wafer polishing consistency. In other embodiments, the CMP pad conditioning system may enable detection of defective or worn CMP pads or pad conditioners, thereby preventing or reducing damage to wafer surfaces and the resulting expense of wafer processing loss. In additional embodiments, the CMP pad conditioning system may enable detection of changes in the chemical or physical characteristics of the polishing slurry, thereby signaling the need to change or modify the slurry properties.

Problems solved by technology

Over time, the surface of the polishing pad becomes glazed with entrained by-products of the polishing process, thereby decreasing the removal rate or polishing uniformity for subsequent wafers.

Images